The present invention relates to hand held cutting tools in general and, in particular, to a hand held groove cutter and angle grinder with portable dust reducing apparatus.
Cutting tools including a rotating disc or saw have long been known. In many applications, it is desirable to reduce the heat of the disc during cutting to prolong the life of the blade. This has been accomplished, in a number of patents, by providing a flow of cooling water onto the cutting blade. For example, such an arrangement is provided for a rotary coal cutting head in AT8801097, EP 235319, and for a mining pick in GB 2135715.
Cutting with many of these tools is problematic due to the dust generated by the cutting. This dust dirties the work area, can make it difficult to see the area being cut, and is often dangerous to breathe. Even the use of a mask is generally not sufficient to prevent the inhalation of dust. However, a flow of cooling water wets the working area, making cutting difficult, so it is not suitable for reducing the quantity of dust.
The problem of dust is particularly serious in mining. A number of machines have been suggested for entrapping dust for use inside mines. These are generally large machines with a water supply provided to spray nozzles which spray water on the coal cutting head to suppress dust. See, for example, GB 1473267, U.S. Pat. No. 4,251,109, U.S. Pat. No. 1,214,918, U.S. Pat. No. 1,346,822, and DE 3838567. These devices require a large reservoir of water, heavy pumps to provide the water to the mining area, and definitely are not portable.
There is also described in WO97/41990 a dust suppressing hood for a rotary cutting disc. The hood includes a semi-circular casing, with multiple water spray nozzles fixed to the internal side faces of the hood and directed at one or both sides of the disc or saw. The dust combines with the water to form a pasty mass which falls from the hood. This device is complex and expensive to manufacture, and does not work well. This device relates to stationary equipment, and includes a bulky and heavy pump, which cannot be carried during use, but must be pulled along the floor behind the user of the cutting tool. In addition, the water supply is the regular water tap at the work site, so the pump must be connected by a flexible hose to the tap. Finally, mud formed by the wet dust tends to clog the water jets. Since the water is under relatively low pressure, the water exits as a spray of relatively large drops, and mud tends to build up at the jet outlet, until the outlet is completely clogged.
Thus, there is a long felt need for a portable, easily carried, light weight device for suppressing dust during cutting with a hand tool, and it would be desirable to have a hand held groove cutter and angle grinder with portable apparatus for suppressing dust.
According to the present invention, there is provided a hand held cutting tool coupled to a portable device for producing a fog-like spray of water droplets near the cutting tool for moistening dust particles generated during cutting.
According to a preferred embodiment of the invention, the cutting tool includes a rotating blade, a blade guard partially covering the blade, a portable source of pressurized water which can be carried on the body of a user holding the cutting tool, and at least one nozzle mounted in the blade guard and coupled to the pump for producing a fog-like spray of water droplets.
According to a preferred embodiment of the invention, the nozzle is a self-cleaning nozzle.
There is also provided in accordance with the invention a hand held groove cutting tool including a pair of rotating blades mounted on an axle, a blade guard partially covering both blades, a portable source of pressurized water which can be carried on the body of a user holding the cutting tool, and at least one nozzle mounted in the blade guard and coupled to the pump for producing a fog-like spray of water droplets.
There is further provided in accordance with the present invention an attachment for a hand cutting tool having at least one rotating blade, the attachment including a portable device attachable to the hand cutting tool for producing a fog-like spray of water droplets near the rotating blade for moistening dust particles generated during cutting.
According to a preferred embodiment, the attachment includes a blade guard arranged to partially cover the rotating blade, a portable source of pressurized water which can be carried on the body of a user holding the cutting tool, and at least one nozzle mounted in the blade guard and coupled to the source of pressurized water for producing a fog-like spray of water droplets.
There is also provided in accordance with the invention a method of reducing dust adjacent a hand held cutting tool including the steps of coupling the cutting tool having a rotating blade to a portable source of pressurized water, mounting the portable water source on the body of a worker holding the cutting tool, cutting with the cutting tool, and simultaneously spraying a fog-like spray of water droplets from the water source through a nozzle adjacent the rotating blade so as to moisten dust particles generated during cutting.